package <%= packageName %>.repository;

import <%= packageName %>.dto.<%= entityName %>Filter;
import <%= packageName %>.entity.<%= entityName %>;
import jakarta.persistence.criteria.Predicate;
import org.springframework.data.jpa.domain.Specification;

import java.util.ArrayList;
import java.util.List;

/**
 * JPA Specification builder for {@link <%= entityName %>}.
 * Uses a single {@code build(filter)} method so the predicate list never explodes.
 * Add a null-check for each field — if the filter field is null it is ignored.
 */
public class <%= entityName %>Specification {

    private <%= entityName %>Specification() {}

    public static Specification<<%= entityName %>> build(<%= entityName %>Filter filter) {
        return (root, query, cb) -> {
            List<Predicate> predicates = new ArrayList<>();

<%_ for (const field of fields) { _%>
            // Filter by <%= field.name %>
            if (filter.get<%= field.name.charAt(0).toUpperCase() + field.name.slice(1) %>() != null) {
<%_ if (field.type === 'String') { _%>
                predicates.add(cb.like(cb.lower(root.get("<%= field.name %>")),
                        "%" + filter.get<%= field.name.charAt(0).toUpperCase() + field.name.slice(1) %>().toLowerCase() + "%"));
<%_ } else { _%>
                predicates.add(cb.equal(root.get("<%= field.name %>"), filter.get<%= field.name.charAt(0).toUpperCase() + field.name.slice(1) %>()));
<%_ } _%>
            }

<%_ } _%>
            return cb.and(predicates.toArray(new Predicate[0]));
        };
    }
}